1. Field of the Invention
The present invention relates generally to a call-waiting interception feature for a communication device connecting a computer to a conventional data-network, and more particularly, to a method for responding to a telecommunication company call-waiting signal by alerting a user when an incoming call is attempted.
2. Discussion of the Relevant Art
A modem is a device that allows both voice and data communications to be transmitted over a single telephone line. A computer that transmits and receives data via the modem, and the telephone line connected therewith, can be used to access various data and services that are available on a data-network. Computers are used to connect to computer networks, such as the Internet, for various purposes. One such purpose may be for receiving or sending electronic mail. Another is for viewing information available to the user. Typically, connection times are long. Sometimes a situation arises wherein an incoming call occurs, while the telephone line is in use in connection with computer access to the Internet.
Call waiting is a feature supplied by telephone companies and implemented by automatic telephone-switching devices. The feature alerts a telephone user of another incoming call from a third party while the user is already engaged in an ongoing call with a second party. Call notification is provided to the user by an audible indication such as a short tone, on the voice channel thereof.
Telephone companies offering call-waiting services provide means by which a person already conducting a telephone call can put on hold the person he is talking to thereby switching to a conversation with another person calling.
After being notified of the call-waiting, the user has a number of options. By virtue of the above-mentioned means the user can interrupt the ongoing call, put the first call on hold and switch to the second call by flashing the hook switch. The party on hold is in idle state at this time. When the user finishes the conversation with the third party, the user flashes the hook switch again to switch back to the original connection.
The user can also take the pending call by hanging up the ongoing call. Following hanging up the ongoing call the telephone will immediately ring due to the incoming call.
The user could also ignore the call-waiting signal and proceed with the ongoing call. In such case, the call-waiting notification will be repeated at least one more time.
Typically, when a modem is used, i.e., the user is connected to a data-network via a modem and a telephone line, the call-waiting feature is lost because the modem is not adapted to respond to the call-waiting signal. In such circumstances, the user will not be aware of the second incoming call.
Call-waiting notification is a disruption of the carrier in the modem. A carrier is a transmitted electromagnetic pulse or wave at a steady base frequency of alternation on which information can be imposed by increasing signal length, varying the base frequency, varying the wave phase, or other means.
All modems consist of a digital part and an analog part. The analog part is connected to the telephone line and is designed to handle incoming wave variations over the telephone line representing voice or data indications. The analog side of the modem is translated to digital indications using conventional (ADC) analog-to-digital converter unit. ADC conversion is an electronic process in which a continuously variable (analog) signal is changed, without altering its essential content, into a multi-level (digital) signal. The characteristics of the incoming variable (analog) signal associated with the notification tone are out of the range of admissible signal variations for data indications. Therefore, the notification by tone of the call-waiting feature cannot be transferred from the analog part to the digital part, without causing actual disconnection of the modem from the telephone line.
Thus, there is a need for a method of identifying the call-waiting feature while the user is connected via a modem to a telephone line.
Several solutions have been proposed to the described problem in the art. Some of the proposed solutions identify the call-waiting signal by using a specially designed modem having the capability to identify the particular attributes of the call-waiting signal analog waveform. Such modems are mechanically altered to achieve said purpose. Therefore said specially designed modem could recognize and consequently handle said signal in association with specifically developed software program.
Other solutions offer a connection to the public switched telephone network (PSTN) thereby to identify the call-waiting signal and then pass the information to the user over the data-network.
Yet another proposed solution involves a simulation of the call-waiting feature by using the call-forward feature. Before connecting to the data-network the user computer exercises the call-forward feature, i.e., dialing 72 or *72 and then a server service telephone number. When a second call is received, the PSTN transfers the second call to the Internet Service Provider (ISP), which notifies the user via the data-network of the incoming call. The dial-up number used for activating the call-forward feature is telephone network-specific. After the termination of the call, it is necessary to cancel the call-forward service by placing another call. It will be appreciated that it would be highly desirable to have a comprehensive solution for the correct recognition and appropriate handling of the call-waiting event. It would also be advantageous to have a solution that comprises software elements implemented on the user computer that applies to all standard modems using AT commands and necessitates no hardware modifications in the modem, the telephony or the Internet Service Provider (ISP).
One aspect of the present invention regards a computerized system that includes a storage device, a communication device, an input/output device and a processing device, wherein a call waiting event interception apparatus operatively loaded into the storage device includes a call waiting event interception component for identifying a call waiting component and a call waiting event handling component.
A second aspect of the present invention regards a computerized system that includes a storage device, a communication device, an input/output device and a processing device, wherein a call waiting event apparatus operatively loaded into the storage device includes a call waiting interception method. The call waiting interception method includes a method for initializing a communication device, a method for measuring round trip time of a data unit from the data network to the computerized system, a method for identifying a call waiting event and a method for responding to a call waiting event.
The first aspect of the present invention provides a novel device for intercepting call waiting events, which overcomes the disadvantages of the prior art.
The second aspect of the present invention provides a novel method for intercepting and properly handling call waiting events, which overcome the disadvantages of the prior art.